1. Field of the Invention
The present invention relates to an internal combustion engine to be mounted in a machine, such as a vehicle, for generating mechanical power through combustion of fuel in the internal combustion engine.
2. Description of the Related Art
To reduce exhaust gases, such as CO2 and NOx, most of diesel vehicles are equipped with exhaust gas recirculation (EGR) systems for recirculating part of the exhaust gas from the internal combustion engines into intake air. The EGR system allows the vehicle to perform a low-temperature combustion by introducing a large amount of exhaust gas after combustion (EGR gas) into the combustion chamber to lower the combustion temperature. Such an EGR system is disclosed in JP-A-H05-163970, for example. To improve the intake efficiency of the internal combustion engines, most of the diesel vehicles are equipped with superchargers for supercharging intake air into the combustion chambers of the internal combustion engines. Such a supercharger is disclosed in JP-U-H04-054926, for example.